HPLC-post column systems for simultaneous determination of lipid hydroperoxides was developed. Lipid hydroperoxides were separated on an ODS column by using a gradient elution mode, then they reacted with diphenyl-1-pyrenylphosphine(DPPP), a fluorescence reagent for lipid hydroperoxides, in a stainless steel coil at 80 C and fluorescence intensity was monitored. By the system, eight kinds of lipid hydroperoxides were separated each other and determined at pmol levels with good reproducibility. The system was successfully down sized to semi-micro system using an 2.0mm i.d. ODS column. The system made it possible to save the amount of a reagent and the solvents by needing less than 1/10 and 1/3, respectively, of the amounts for the conventional size system without reducing sensitivity and reproducibility. By using ph-silica column instead of an ODS column, it was possible to separate lipid hydroperoxides on their class levels. These systems allowed us to inject 90 ul of sample in MeOH/chloroform(1 : 1)by slightly modification of an injection port.By using these systems, we showed that the X(active oxygen species)-Y(catalyst)-Z(oxygen acceptor)chemiluminescence system played as a scavenging system of lipid hydroperoxides in the presence of Mn^<2+>. We also showed that some beverages had strong lipid hydroperoxide scavenging activity.